Fire detecting device



Dec. 28, 1965 5, F|NKLE 3,226,703

FIRE DETECTING DEVICE Filed Nov. 19, 1962 2 Sheets-Sheet l INVENTOR. SAMM. FINKLE ATTORNEY Dec. 28, 1965 s. M. FINKLE 3,

FIRE DETECTING DEVICE Filed Nov. 19, 1962 2 Sheets-Sheet 2 FIG. 4

5/ i FIG. 5

IN VENTOR.

BY L54 A512 @W ATTORNEY SAM M. FINKLE United States Patent 3,226,703FIRE DETECTING DEVICE Sam M. Finkle, 6567 Gundry Ave., Long Beach 5,Calif. Filed Nov. 19, 1962, Ser. No. 238,545 Claims. (Cl. 340-237) Thepresent invention relates generally to fire alarm or warning systems andconcerns itself more particularly with a smoke detecting device which iscapable of giving a much earlier warning than heretofore known to theart.

Fire detecting systems found in the prior art usually take the form of asmoke sensitive or heat sensitive device or a combination of both whichrely principally upon the generation of, or interruption of, anelectrical signal initiated by the action of either one or a combinationof both of such devices.

Normally, the heat sensitive devices employed take the form of athermostat which is used to open or close an electrical circuit toproduce the required warning signal. Similarly, the smoke sensitivedevices employed utilize an electrical transducer which may be one ofthe photo-conductor, photo-emissive or photo-voltaic types, whosecurrent carrying characteristics are altered to effect the warningsignal by changes in the intensity of light rays directed against thetransducer as brought about by the presence of smoke arising from thefire to be detected.

These basic teachings have been employed in various ways in the priorart with reasonable success, but have, in the main, failed to detectfires in their incipient state. In the case of heat sensitive devicesalone, the fire must have progressed to a point where suflicient heat isgenerated to actuate the thermostatic element of the unit, andheretofore where light sensitive devices alone were used it has beennecessary that considerable smoke be present before detection waspossible.

By novel structural and circuitry arrangements, I have made substantialimprovements over the prior art smoke detecting devices to the end thatsome of the foregoing disadvantages have been overcome and the primaryobjectives of my invention have been accomplished.

More specifically, the primary purpose of the invention, which is toprovide a smoke detecting device capable of warning the presence ofincipient fires, has been accomplished.

Another object of the invention is to provide a smoke detecting devicewhich may be used with any existing heat actuated fire alarm orsprinkler supervisory system regardless of the type of control panelemployed in the system.

A further object of the invention is to provide a device of the typedescribed which when installed cannot be removed or tampered withwithout causing an alarm signal to be given.

Yet another object of the invention is to provide a smoke detecting unitwhich is reasonably simple in construction, is easy to maintain andoperate, and attractive in appearance to blend with the decor of anyroom or structure in which it is installed.

Other objects and advantages of the invention will become apparent asthe description proceeds, and a more comprehensive understanding of theinvention will be afforded from the following detailed specificationwhen considered in conjunction with the accompanying drawings forming apart thereof, and in which:

FIGURE 1 is a fragmentary perspective view of a room illustrating atypical installation of the fire detecting unit of the subjectinvention;

FIGURE 2 is a bottom plan view of the unit;

FIGURE 3 is a perspective cut-away view showing in assembled fashion theunits housing, chassis, light shield and snap-on cover, and the relativepositions of "ice its light sensitive resistors with respect to a lightsource and the smoke chambers formed in said chassis;

FIGURE 4 is a partial sectional view of the unit taken along the line 44of FIGURE 2; and

FIGURE 5 is a schematic view showing the detection unit and itscircuitry as invention. Like reference numerals have been used in thedifferent views to designate like parts.

By way of general description, the invention is practiced in one of itsembodiments by arranging in each of two arms of a Wheatstone bridge, atransducer or light sensitive resistor, with the other two arms of thebridge being formed, respectively, by segments of the resistance windingof a potentiometer. A low voltage, either AC. or D.C., is impressedacross the bridge circuit thus formed, and signal leads are taken fromthe sliding contact of the potentiometer as one null point and the othernull point of the bridge circuit.

The bridge is then adjusted to a null condition by the potentiometer. Anincandescent lamp is associated with the bridge circuit, and is mountedin a chassis in which are formed smoke chambers. Likewise, a reflectingsurface mirror is mounted in the chassis so as to reflect light from thelamp through one smoke chamber to one of the light sensitive resistors,and the second light sensitive resistor is associated with its smokechamber to receive the rays from the lamp by reflection and refractionfrom smoke particles in this chamber.

Thus, smoke arising from the fire to be detected is allowed to enter thefirst smoke chamber to decrease the intensity of light passing byreflection from the mirror to the first transducer and into the secondsmoke chamber to increase the intensity of the light falling on thesecond transducer. In this manner the bridge circuit is unbalanced and awarning signal is passed through the signal leads to a transistorizedamplifier and thence through a control circuit to complete the alarm orwarning.

A heat detector, taking the form of a bimetallic switch or a rate ofrise type, is inserted in series with one of the transducers to detectfires which produce imperceptible amounts of smoke. This normally closedbimetallic switch opens under the influence of heat to unbalance thebridge circuit and generate the warning signal as previously described.

Referring now to the drawings, the self-contained fire detecting unit11, FIGURE 2, of the present invention, which may be installed in a roomor other enclosure 12 as shown in FIGURE 1, comprises in part a housing13, FIGURES 3 and 4, a chassis 14, a cover 15, and a mounting plate 16.

The chassis 14 is secured to the mounting plate 16 by a screw 17 andcircumferentially extending ring 18 of epoxy cement or other bondingagent, as may best be seen in FIGURE 4. Housing 13 is fastened tochassis 14 by means of a few bayonet type hooks 13a to provide an airduct 13b between housing 13 and chassis 14, as well as other portions ofthe device as illustrated in FIGURE 4. The mounting plate 16 is attachedto the housing 13 by countersunk screws 21. The cover 15 is removablyattached to the housing 13 through the agency of a light shield 22attached to the cover 15 by countersunk screws 23. In this instance therounded surface 24 of the light shield 22 engages in an annulusdepression 25 cut in the housing 13 to attach the cover 15 to the latterin snap-on fashion.

A concentric port 26 is provided between the light shield 22 and thecover 15 which permits smoke-contaminated air to pass into the unit 11as indicated by the arrows shown in FIGURE 4. The smoke-contaminated airis passed out of the unit through a series of vents 27 opened in thehousing 13.

'ing 13 for accessibility outside the unit.

The entire unit 11 may be installed by attachment to a-standard plasterring 19 by screw headed bolts 28 passed through holes 29 (FIGURE 3) inthe chassis 14 and plate 16. Housing 13'including cover 15 are concurrently removed to attain access to these .screws. In the alternate,the unit may be attached by wood screws used in place of the bolts 28which are passed through the holes 29 for direct connection to a wall orceiling.

Within the unit 11 there is contained a heat detecting element 31(FIGURE 4) which is retained in a centrally located bore 32 in the cover15 to present a heat sensitive surface 33 thereof external to the unit.The element 31 is secured to the cover 15 by two screws 34 which serveas contacts.

The chassis 14, which is cylindrical in shape, has sections removed(FIGURE 3) to form two smoke chambers 35 and 36, and three receptacles37, 38 and 39. Also, the chassis 14 has a groove 41 channeled thereinextending transversely thereof to a depth of a little more than theheight of the smoke chambers. A second groove receptacle 38 houses anincandescent lamp 45, the light from which is diffused in the smokechamber 36 and which is reflected from a mirror 46 mounted in the groove42 along the smoke chamber 35, all in a manner to be described morecompletely herein. The groove 41 in the chassis 14 retains a glued-ontranslucent dust the two transducers 43 and 44 from airborne particlessuch as dust, and minimizes the possibility of the tampering with thetransducer and lamp. Also mounted on the chassis 14 in a compartmenttherein (not shown) is a potentiometer 48 shown schematically in FIGURE5 which has an adjustment screw or member 49 that projects outwardlythrough an opening formed in the hous- This adjustment screw can be andis preferably factory set.

While no limitation on the invention is to be inferred from the teachingpertaining to the use of any particular materials or elements, thehousing 13', the chassis 14,

and the cover 15 are formed preferably from a'heat resistant phenolicplastic. The light shield 22 is made of metal such as brass to give itrigidity and longer wear in performing its secondary function as thesnap-on mounting for the cover 15. The mounting plate 16 may be made ofmicarta or some other suitable plastic. All of the elements contained inthe unit such as the lamp, potentiometer and transducers may takeanysuitable form of those available on the commercial market.

With reference to FIGURE 5, the electrical elements,

mountedin the unit as previously described, are opera-.

tively connected as shown. Here the transducer 43, which in theillustrated embodiment takes the form of a cadmium sulphide resistor (orphoto-electric cell) has connected in series with it, a bimetallicswitch 51 of the heat detecting device 31 (FIGURE 4) to form one arm ofa Wheatstone bridge. The transducer 44, which may also take the form ofa cadmium sulphide resistor, forms the second arm of the bridge and thesegmented portions 52 and 53 of the resistance winding of thepotentiometer 48, together with their connecting conductors, formrespectively the third and fourth arms of the bridge circuit describedas AB, BC, CD and DA.

A potential from a power supply source 54, which may be either AC. orDC. is impressed upon the bridge circuit ABCD through the conductors 55and 56 and signal leads 57 and 58 are taken respectively from the nullpoints D and B of the bridge circuit ABCD to a transistorized amplifier59, with the lead or conductor 57 having a variable resistance 61connected therein to adjust the sensitivity of the signal received bythe amplifier 59.

The output of the amplifier 59 is fed to a relay which energizes analarm circuit 63 to give either a visible or audible warning or both, orto operate a sprinkler system control. The amplifier 59 and relay 62 areexternal to the unit 11 as well as the power source 54. In the case ofthe latter, a 22-volt D.C. which is regulated to a constant voltage ispreferred. However, an AC. source may be used directly or it may berectified and regulated. A bridge-type rectifier 64 is mounted in thechassis 14. The input may vary due to the fact that the resistance ofthe cells will not always be the same and, therefore, their outputs maybe going in either direction in respect to the null position. The outputof the rectifier bridge will always be the same polarity and, therefore,not cancel out the possible different potentials from other units on thesame circuit.

Within the unit, all wires connecting the above described elements arecarried in runs channeled in the plastic members 14, 15 and 16. Thewarning signal output of the bridge circuit ABCD is carried by leads totwo contact posts 65 and 66 mounted for easy accessibility on the topside of the mounting plate 16. Two other contact posts 67 and 68similarly mounted have leads connecting them with the bridge circuitryat A and C.

The amplifier 59 receives power through the com ductors 69 and 71 fromthe same as does the bridge circuit and lamp 45, which latter device hasconnected in series therewith a variable resistor 72 used to adjust theintensity of the light produced by'the lamp 45,

The unit 11 is installed by first connecting the wires from an outletreceptacle (not shown) to their proper connecting posts .65, 66, 67 and68. The unit is then attached to the outlet receptacle or a plastic ring(not shown) and the cover 15 is snapped into place. After the unit ismanufactured and before delivery to a job site, electric current issupplied thereto, and the intensity of the light from lamp 45 isproperly adjusted by the resistor 72. The potentiometer 48 is alsoadjusted at the factory to bring the bridge into its null state and theunit in condition for detecting a fire and giving a warning signal.

Since in its non-detecting state no current is supplied to theamplifier, several units may be connected in parallel and thesensitivity control 61 may be employed at the amplifier input forsensitivity control.

With a unit properly installed and adjusted as described above, it isconditioned to detect a flash fire (large flames and little smoke)through the action of its heat sensitive device 31. In such case, wherethe temperature of the ambient air rises above a predetermined degreefixed as the setting of the devices thermostatic element, the bimetallicswitch 57 opens the bridge circuit ABCD and the latter is unbalanced.Current then flows across its null points and the signal thus generatedis fed to the amplifier 59. The output of the amplifier 59 energizes therelay 62 which in turn causes the control warning circuit 63 to beenergized and give the alarm or effect remedial action or both.

Where the fire in its incipient stage generates a large 'quantity ofsmoke and little flame, the unit is capable of detecting the fire in itsvery early stage, before the ambient temperature rises perceptively.Detection is effected as will be described with reference to FIGURES 3,4 and 5.

Thus, the smoke first generated by the smouldering fire arises to enterthe unit 11 through the port 26, from which point it quickly passes intoand fills the smoke chambers 35 and 36. With reference to FIGURE 5, itwill be seen that through the agency of the novelly arranged smokechamber, the transducers and the mirror, the direct light rays r-r' fromthe lamp 45 to the mirror 46 and the reflected rays r'-r from the mirrorto the transducer 43 are decreased in intensity by the presence of thesmoke in both chambers 35 and 36, and that conversely the light raysreceived by the transducer 44 are increased in intensity due to theirreflection from the thousands of smoke particles in chambers 36.

Hence, the resistance of the transducer 43 increases with the decreaseof light intensity directed thereon and the bridge circuit ABCD becomesunbalanced. Conversely, since the light intensity falling on transducer44 is increased, its resistance. decreases and becomes additive,circuit-wise, to the effect of the transducer 43 in unbal'an'cing thebridge. Thus, small traces of white or light colored smoke is sufiicientto activate the detection circuitry and give a much, much earlierwarning than heretofore achieved. However, the device is activated byblack or dark colored smoke entering the chambers 35 and 36. Such smokeif in quantity will be substantially opaque, and little light will bereflected t-o transducers 43 or 44. .The resistance of transducer 43increases, and the bridge is unbalanced, with resultant actuations ofthe alarm. The alarm is accordingly energized by the presence of whiteor light colored smoke that is transparent to a degree in chambers 35and 36, or dark or black smoke in these chambers which may be opaque. Inthe operation of the device the lamp 45 will obviously heat the airinside the housing 13, with cool air from the room 12 entering thedevice through the port 26 as shown in FIGURE 4, and heated air in thehousing escaping through the vents 27.

Although a particular embodiment of the invention has been described, itis possible that the same may be practiced in other ways. Insofar asthese other practices fall within the scope of the appended claims, theyare to be considered to be included as if described.

I claim:

1. In a fire detecting device, the combination of:

(a) a first light sensitive resistor connected to form one arm of aWheatstone bridge;

(b) a second light sensitive resistor connected to form a second arm ofsaid bridge and provide a null point between said first and second arms;

(c) a potentiometer having first and second segmented portions of itsresistance winding connected to from respectively third and fourth armsof said bridge and a movable contact to adjust said potentiometer toeffect a balance of said bridge and with said resistance winding form asecond null point on said bridge;

(d) an electrically energized source of light;

(e) an electric circuit for supplying electric energy to said first andsecond resistors, said third and fourth arms of said bridge, and saidsource of light;

(f) a mirror;

(g) an opaque housing located at an elevated position over an area thatis to be protected from fire, said housing having two elongate smokechambers therein that are angularly disposed relative to one another,said mirror being located in said housing at the junction of saidchambers and said first resistor at a first end of said first chamber,and said second resistor at a first end of said second chamber, withsaid source of light being so located inside said housing that a beam oflight therefrom falls on said mirror, said mirror being so disposed insaid housing that said beam of light is reflected through said firstsmoke chamber to fall on said first resistor, a port formed in the lowerpart of said housing and at least one vent formed in the upper portionthereof, and said source of light heating the interior of said housingto the extent that cool air from the ambient atmosphere is continuouslydrawn into the interior of said housing to replace heated air in saidhousing that escapes upwardly through said vent;

(h) an electrically operated alarm that forms a part of said circuit andis energized by the unbalance of said bridge, with said unbalanceoccurring when white smoke is drawn into said housing due to the escapeof heated air therefrom in a sufficient quantity that the intensity ofthe beam of light reflected to said first resistor is decreased toincrease the resistance of said first resistor and the individualparticles of said white smoke in said housing serve as a reflectorymedium to reflect a portion of said beam of light to said secondresistor to decrease the resistance thereof, and said unbalanceoccurring when black smoke is drawn into said housing in such quantityas to substantially obstruct the passage of the reflected beam of lightfrom said mirror to said first resistor, as well as the reflection of aportion of said beam of light by the particles in said black smoke tosaid second resistor.

2. In a fire detecting device, the combination as claimed in claim 1,including:

(a) a normally closed heat sensitive switch connected in series withsaid first light sensitive resistor and arranged to be responsive to theheat generated by the fire to be detected to open said bridge circuitand thereby effect an unbalance thereof causing a signal voltage toappear across said first and second null points of said bridge.

3. In a fire detecting device, the combination as claimed in claim 1including:

(a) an amplifier in said circuit for receiving the signal voltage fromthe null points of said bridge; and

(b) means responsive to the output of said amplifier to cause said alarmto be energized to give warning of the existence of said fire.

4. In a fire detecting device, the combination as claimed in claim 1,including:

(a) a rectifier in said electric circuit for receiving the signalvoltage appearing across the null points of said bridge;

(b) an amplifier in said electric circuit for receiving the output ofsaid rectifier; and

(0) means forming a part of said circuit responsive to the output ofsaid amplifier to energize said alarm.

S. In a fire detecting device, the combination of:

(a) a first light sensitive resistor connected to form one arm of aWheatstone bridge;

(b) a second light sensitive resistor connected to form a second arm ofsaid bridge and provide a null point between said first and second arms;

(c) a potentiometer having first and second segmented portions of itsresistance winding connected to form respectively third and fourth armsof said bridge and a movable contact to adjust said potentiometer toeffect a balance of said bridge and with said resistance winding form asecond null point on said bridge;

(d) an electrically energized light source so arranged that the raysthereof impinge continuously upon said first light sensitive resistor;

(e) a chassis on which first and second light sensitive resistors andsaid light source are mounted, which chassis has a first smoke chambertherein open to the light from said source and so arranged as totransmit light to said first light sensitive resistor, with said chassishaving a second smoke chamber communicating with said first smokechamber that is so arranged as to receive and transmit light refiectedfrom individual smoke particles to said second light sensitive means,and smoke from said fire conductive into said smoke chamber decreasingthe intensity of light transmitted to said first light sensitive meansand increasing the intensity of light transmitted to said second lightsensitive means;

(f) an electric circuit for supplying electric energy to said first andsecond resistors and said light source;

(g) a mounting plate for supporting said chassis;

(h) a housing enclosing said chassis attached at one end to saidmounting plate to form vent openings in said housing and open at itsother end;

(i) a cover for closing the open end of said housing; (j) a light shieldattached to said cover, said light shield having a surface thereofarranged to engage a groove in said housing in snap-on fashion, whichcover and light shield are connected to form a port, with said source oflight heating the interior of said housing to the extent that cool airfrom the ambient atmosphere is continuously drawn into the interior ofsaid housing to replace heated air in said housing that escapes upwardlythrough said vent;

(k) an electrically operated alarm that forms a part of said circuit andis energized by the unbalance of said bridge, with said unbalanceoccurring when white smoke is drawn into said housing due to the escapeof heated air therefrom in a sufficient quantity that the intensity ofthe beam of light reflected to said first resistor is decreased toincrease the resistance of said first resistor and the individualparticles of said white smoke in said housing serve as a refiectorymedium to reflect a portion of said beam the reflected beam of lightfrom 'said mirror to said,

first resistor, as well as the reflection of a'portion of said beam oflight by the particles in' said black smoke to said second resistor.

References Cited by the Examiner UNITED STATES PATENTS 2,301,367 11/1941Chausac et a1. 340-228 2,583,930 1/1952 Cotton '340-237 2,604,597 7/1952Cahusac et al. 340-237 2,737,642 3/1956 Schafer 340-233 2,797,336 6/1957Loft 250239 2,901,740 8/1959 Cutsogeorge 340233, 2,918,585 12/1959Farmer 250239 2,982,950 5/1961 Boyle 340237' 3,056,123 9/1962 Shamos 1340-237 NEIL C. READ, Primary Examiner.

5. IN A FIRE DETECTING DEVICE, THE COMBINATION OF: (A) A FIRST LIGHT SENSITIVE RESISTOR CONNECTED TO FORM ONE ARM OF A WHEATSTONE BRIDGE; (B) A SECOND LIGHT SENSITIVE RESISTOR CONNECTED TO FORM A SECOND ARM OF SAID BRIDGE AND PROVIDE A NULL POINT BETWEEN SAID FIRST AND SECOND ARMS; (C) A POTENTIOMETER HAVING FIRST AND SECOND SEGMENTED PORTIONS OF ITS RESISTANCE WINDING CONNECTED TO FORM RESPECTIVELY THIRD AND FURTH ARMS OF SAID BRIDGE AND A MOVABLE CONTACT TO ADJUST SAID POTENTIOMETER TO EFFECT A BALANCE OF SAID BRIDGE AND WITH SAID RESISTANCE WINDING FORM A SECOND NULL POINT ON SAID BRIDGE; (DX) AN ELECTRICALLY ENERGIZED LIGHT SOURCE SO ARRANGED THAT THE RAYS THEREOF IMPINGE CONTINUOUSLY UPON SAID FIRST LIGHT SENSITIVE RESISTOR; (E) A CHASSIS ON WHICH FIRST AND SECOND LIGHT SENSITIVE RESISTORS AND SAID LIGHT SOURCE ARE MOUNTED, WHICH CHASSIS HAS A FIRST SMOKE CHAMBER THEREIN OPEN TO THE LIGHT FROM SAID SOURCE AND SO ARRANGED AS TO TRANSMIT LIGHT TO SAID FIRST LIGHT SENSITIVE RESISTOR, WITH SAID CHASSIS HAVING A SECOND SMOKE CHAMBER COMMUNICATING WITH SAID FIRST SMOKE CHAMBER THAT IS SO ARRANGED AS TO RECEIVE AND TRANSMIT LIGHT REFLECTED FROM INDIVIDUAL SMOKE PARTICLES TO SAID SECOND LIGHT SENSITIVE MEANS, AND SMOKE FROM SAID FIRE CONDUCTIVE INTO SAID SMOKE CHAMBER DECREASING THE INTENSITY OF LIGHT TRANSMITTED TO SAID FIRST LIGHT SENSITIVE MEANS AND INCREASING THE INTENSITY OF LIGHT TRANSMITTED TO SAID SECOND LIGHT SENSITIVE MEANS; (F) AN ELECTRIC CIRCUIT FOR SUPPLYING ELECTRIC ENERGY TO SAID FIRST AND SECOND RESISTORS AND SAID LIGHT SOURCE; (G) A MOUNTING PLATE FOR SUPPORTING SAID CHASSIS; (H) A HOUSING ENCLOSING SAID CHASSIS ATTACHED AT ONE END TO SAID MOUNTING PLATE TO FORM VENT OPENINGS IN SAID HOUSING AND OPEN AT ITS OTHER END; (I) A COVER FOR CLOSING THE OPEN END OF SAID HOUSING; (J) A LIGHT SHIELD ATTACHED TO SAID COVER, SAID LIGHT SHIELD HAVING A SURFACE THEREOF ARRANGED TO ENGAGE A GROOVE IN SAID HOUSING IN SNAP-ON FASHION, WHICH COVER AND LIGHT SHIELD ARE CONNECTED TO FORM A PORT, WITH SAID SOURCE OF LIGHT HEATING THE INTERIOR OF SAID HOUSING TO THE EXTENT THAT COOL AIR FROM THE AMBIENT ATMOSPHERE IS CONTINUOUSLY DRAWN INTO THE INTERIOR OF SAID HOUSING TO REPLACE HEATED AIR IN SAID HOUSING THAT ESCAPES UPWARDLY THROUGH SAID VENT; (K) AN ELECTRICALLY OPERATED ALARM THAT FORMS A PART OF SAID CIRCUIT AND IS ENERGIZED BY THE UNBALANCE OF SAID BRIDGE, WITH SAID UNBALANCE OCCURING WHEN WHITE SMOKE IS DRAWN INTO SAID HOUSING DUE TO THE ESCAPE OF HEATED AIR THEREFROM IN A SUFFICIENT QUANTITY THAT THE INTENSITY OF THE BEAM OF LIGHT REFLECTED TO SAID FIRST RESISTOR IS DECREASED TO INCREASE THE RESISTANCE OF SAID FIRST RESISTOR AND THE INDIVIDUAL PARTICLES OF SAID WHITE SMOKE IN SAID HOUSING SERVE AS A REFLECTORY MEDIUM TO REFLECT A PORTION OF SAID BEAM OF LIGHT TO SAID SECOND RESISTOR TO DECREASE THE RESISTANCE THEREOF, AND SAID UNBALANCE OCCURING WHEN BLACK SMOKE IS DRAWN INTO SAID HOUSING IN SUCH QUANTITY AS TO SUBSTANTIALLY OBSTRUCT THE PASSAGE OF THE REFLECTED BEAM OF LIGHT FROM SAID MIRROR TO SAID FIRST RESISTOR, AS WELL AS THE REFLECTION OF A PORTION OF SAID BEAM OF LIGHT BY THE PARTICLES IN SAID BLACK SMOKE TO SAID SECOND RESISTOR. 